29 October 2017

Disclaimer: Weather is a mix of pattern and chaos; these ideas are from the patterned world.

SOUTH PACIFIC TROPICAL CYCLONE SEASON STARTS on WEDNESDAY

Another good website for watching out for Tropical disturbances is www.tropicaltidbits.com/storminfo/

This site combines information from a number of websites dedicated to watching tropical disturbances. When using it, remember that your insurance companies will mainly be interested in if you heed information that comes from the OFFICAL warning agencies, and in our part of the world that’s Fiji Met Service or NZ MetService (websites given in last weathergram) and, around Australia , the Bureau of Meteorology.

See www.bom.gov.au/qld/forecasts/cyclone.shtml for the Coral Sea region.

TROPICS

TC PHILIPPE formed over Cuba in the past day or so and is now heading northeast where it is likely to follow the Gulf Stream. This system may re-intensity into a mid-latitude system in a few days, thus have a stronger spin of wind around it and get deflected to the northwest and inland near New York. If so it has the potential to deepen to 970hPa and bring a northwest gale to Lake Ontario. Reminds me of Gordon Lightfoot’s ‘Wreck of the Edmund Fitzgerald “(in Lake Superior, 10 Nov 1975)) with lyrics: “When the gales of November come early” see www.youtube.com/watch?v=9vST6hVRj2A

In the NW Pacific TC SAOLA is forming over Micronesia near Guam and is expected to travel NW then N towards Japan.

Looking at the weekly rain maps at trmm.gsfc.nasa.gov/trmm_rain/Events/big_global_accumlation.gif from last week and the week before, we can see a burst of heavy rain in the past week around central America and Guam., and another near the central Pacific to the north of Hawaii. Intensity seems to be easing around India, in the ITCZ across the North Pacific and in the SPCZ across the South Pacific.

WEATHER ZONES

SPCZ=South Pacific Convergence zone.

The SPCZ is expected to stay where it is, from Solomon Islands to northern Vanuatu to northern Fiji to between Samoa and northern Tonga to between Niue and Southern Cooks. Any voyage from Tahiti to Tonga will need to sail/motor thru the SPCZ and it is likely to breed several squally showers this week. Avoid.

Subtropical ridge (STR)

There is a Big Fat High (BFH) HIGH east of NZ from Monday to Thursday. This is being supported by a break in the normal upper level Jet Stream pattern, and is indicated by the mid atmosphere (500hPa level) wind map showing the shape of the Greek Capital Letter Omega, but upside down in the Southern Hemisphere.

The left and right hooks of the OMEGA are associated with surface lows.

So, this BFH is expected to BLOCK the troughs in the Tasman Sea this week and redirect them AROUND New Zealand rather than onto NZ.

For more about the Omega pattern see en.wikipedia.org/wiki/Block_(meteorology)

From Friday this block is expected to weaken, and the surface high should relax and move off to the northeast, allowing a new HIGH to travel east across Tasmania into the Tasman Sea from Saturday.

Between Tropics and NZ

There is a squash zone of strong east to NE winds between the BFH and the tropics.

Those departing from Fiji or New Caledonia to NZ should arrange their voyage so that they do not get near NZ until after Thursday.

This squash zone is expected to visit the Minerva/ South Tongan area from Tuesday to Thursday, so stay put for that. Should be able to depart Tonga or Minerva from Friday, but may need to try and time your departure taking into account south to southwest winds near NZ.

The next trough to reach northern NZ is likely around 5 to 6 November.

Between New Caledonia and Australia

Looks ok for departure Noumea any day this week.

The trough crossing Brisbane on Monday is expected to deepen into a low in central Tasman Sea by Tuesday, but the BFH should push that off to the south so it just fades away on the Noumea to Brisbane route.

Next intense thundery trough is expected to reach Brisbane/Bundaberg area around late Mon 6 November or Tuesday7 November, so avoid that as arrival date.

“I can't control the wind but I can adjust the sail.”

― Ricky Skaggs

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If you would like more detail for your voyage, then check metbob.com to see what I offer.

Feedback to bob@metbob.com or txt 6427 7762212

Weathergram text only (and translator) is at weathergram.blogspot.co.nz.

Weathergram with graphics is at metbob.wordpress.com,

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22 October 2017

Disclaimer: Weather is a mix of pattern and chaos; these ideas are from the patterned world.

TROPICAL CYCLONE SEASON

Now that the tropical cyclone season is almost upon us, here are some links for you to check the latest. The Fiji Met Service watch for disturbances between equator and 25S from 160E to 120W. Even if you have no Internet access, and only email, you can get the latest tropical disturbance advisory by sending an email to query@saildocs.com,

no subject needed, with the message

SEND http://www.met.gov.fj/aifs_prods/20032.txt

Or, for the tropical discussion use

SEND http://www.met.gov.fj/aifs_prods/20036.txt

(wait until after 1 November)

Those with access to the Internet can study proceedings from the NZ MetService Tropical page at www.metservice.com/warnings/tropical-cyclone-activity

TC LAN is bringing wind and rain to eastern Japan tonight, in time for a snap election.

And this is being followed bu tropical depression TD27W which may intensify later this week and head for Japan.

see www.tropicaltidbits.com/storminfo/

Looking at the weekly rain maps from last week and the week before, we can see a burst of heavy rain in the past week with cyclones between Guam and Japan, also intense rain on the Intertropical convergence zine just south of Hawaii. The South Pacific Convergence zone also shows an intensification in the past week. The Madden Julian Oscillation MJO is in phase with the Western Pacific this coming week, and that suggests we can expect more intensification along the ITCZ in the North Pacific this week.

See trmm.gsfc.nasa.gov/trmm_rain/Events/big_global_accumlation.gif

WEATHER ZONES

SPCZ=South Pacific Convergence zone.

The SPCZ is expected to remain lingering in place this week from Solomon Islands to Tuvalu/Tokelau area. It may drift south onto Fiji/Samoa and northern Tonga/Niue next week or around the end of the month.

A passing trough is expected to visit northern NZ to New Caledonia on Monday and South Fiji to Minerva area on Tuesday and Wednesday then fade away. It may contain a few squalls. Tropical accumulated rainfall for next week can ve seen at windyty.com

Subtropical ridge (STR)

HIGH is expected to travel east along 30S across the Tasman sea from Monday to Thursday reaching to east of northern NZ on Friday.

Another HIGH is expected to travel across the South Tasman Sea along 40S from Wednesday to Friday, then it may build to east of NZ over the weekend and next week (but models differ on this).

Between Tropics and NZ

The High crossing the Tasman Sea/northern NZ area this week offers a reasonable period of settled weather for getting to NZ. The trough that follows this High is expected to reach northern NZ on Wednesday 1-2 November so try and not arrive on those dates.

If this means arriving a few days later, that’s OK, we can arrange to sail thru the passing trough around 30S where its weak.

The next trough to reach northern NZ is likely around 5 to 6 November.

Between New Caledonia and Australia

Stay put on Monday and let a passing trough get across New Caledonia. Should be OK to depart from Tuesday, but departures on Tuesday to Friday will likely encounter a period of light winds from a passing ridge.

Try and avoid arriving on Queensland coast on late Monday 30 Oct/Tuesday 31 Oct due to a possible passing trough.

Note that New Caledonia and French Polynesia have a public holiday on Wed 1 November.

“The pessimist complains about the wind,

the optimist expects it to change soon,

and the realist adjusts the sails”

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If you would like more detail for your voyage, then check metbob.com to see what I offer.

Feedback to bob@metbob.com or txt 6427 7762212

Weathergram text only (and translator) is at weathergram.blogspot.co.nz.

Weathergram with graphics is at metbob.wordpress.com,

Click FOLLOW at bottom right to subscribe.

To unsubscribe from WordPress: click the “unsubscribe” link on the bottom of the email.

Or, if email wasn’t from WordPress then send a reply email saying LEAVE.

15 October 2017

Disclaimer: Weather is a mix of pattern and chaos; these ideas are from the patterned world.

TROPICAL CYCLONE SEASON OUTLOOK

The South Pacific/Australian tropical cyclone season is nominally from 1 Nov to 30 April. A weak to briefly moderate LA NINA is expected to affect the tropical Pacific Ocean over the next six months. This tends to nudge the South pacific convergence zone to the south and west of its normal position, increasing the cyclone risk around Australia and Coral Sea, and perhaps reducing this risk in places east of the dateline.

The Bureau of Meteorology have considered this and say that the cyclone risk over Northern Australia is increased. The average number of cyclones per season across the entire region is 11. Chances of more this season are 56%.

Looking at the behaviour of the sea surface temperature over the past year, NIWA has searched the database for analogue years that may point the way as to how this season may develop. The top analogues are 1970/71, 1978/9, 1995/96, 2005/6, and 2007/8, and using this data they have compiled some cyclone risk maps.

In summary, NIWA and MetService is anticipating 8 to 10 named storms this coming season (compared to an average of 10.4), a normal to above normal risk for New Zealand, New Caledonia, and Papua New Guinea (mainly late in the season), and a below normal risk for the southern Cook Islands, the Marquesas, and French Polynesia.

For more details see www.scoop.co.nz/stories/SC1710/S00022.htm

Addendum to last week’s comment on Fleet code:

Chuck and Linda on JACARANDA say that :Once we open the email from saildocs we <Right> click the data. A window opens up with some choices and we choose <export> The next window asks us where we want to export the data. We have a folder already created called "Fleet Code". We then just click <save> We also use OpenCPN as we like to see the data on an easier identified chart of the SP. But we have also used Physplot in the past with good results.

Tropics

During the past week a suprising development occurred in the mid North Atlantic ocean: TC OPHELIA, the strongest such system this far east in the North Atlantic. Warmer seas are the most likely explanation for this. And its heading for Ireland on local Monday. Reminds us of “The Great Storm” 30 years ago in October 1987, but this one is likely to bring warm dry gusty winds to southern UK.

And over in the China Sea we have TC KHANUN heading for South China.

see www.tropicaltidbits.com/storminfo/

Looking at the weekly rain maps from last week and the week before, we can see a shift of heaviest rain from equatorial Indian Ocean to The Vietnam/Philippines region, and an easing of the rain over central America. There is also a stretching-southeastwards of the rain in the South Pacific.

See trmm.gsfc.nasa.gov/trmm_rain/Events/big_global_accumlation.gif

WEATHER ZONES

SPCZ=South Pacific Convergence zone.

The SPCZ has been lingering in place this week from Solomon Islands to Tuvalu/Tokelau area and is expected to spread onto Fiji/Samoa and norther Tonga later this week.

An upper trough that is over the Niue area for the next few days is expected to descend and form a surface Low near 35S 165W by Thursday UTC. This low is then expected to deepen as it travels south into the Southern Ocean, leaving a trough over the Niue/Southern Cooks area by the end of the week.

Subtropical ridge (STR)

HIGH is in the central Tasman Sea tonight is expected to build to over 1032hpa by Wednesday and then slowly weaken and travel east along 30S this weekend to east of the dateline next week. There is expected to be a squash zone of enhanced trade winds and rough seas on the north side of this High, mainly between 20 and 25S from 175E to the Queensland coastline on Wednesday/Thursday.

French Polynesia to the west:

Be mindful of the trough that is in the Niue to Southern Cooks area this week.

From tropics to NZ or Australia

The Island Cruising Association are supporting the All Points Rally, from all major parts of South Pacific to Opua ending in ten days of activities 15 to 25 November in Opua. Boats joining the rally are assisted with weather info, resources and planning tools to help make the passage to NZ as easy as possible. See www.bayofislandsmarina.co.nz/all-points-rally/ to register.

Further west there is the GO WEST Rally. From New Caledonia to Australia, culminating with Welcome week events in Bundaberg, 6-12 November. It’s NOT too late to join the rally and enjoy a tailored voyage. See www.downunderrally.com. Registration includes standard Australian clearance fees, and these can be around $A400.

Between Tropics and NZ

The High crossing the Tasman Sea is expected to bring lots of southerly winds south of 30S until Wednesday and then the squash zone associated with High may bring some strong SE winds near 25 to 30S on Thursday. The High is expected to be followed by a FRONT reaching northern NZ on Sun 22 Oct, so avoid landing then. That should be followed by OK conditions for arriving in northern NZ from Mon 23 to Thursday 26 Oct, and then a FRONT to avoid on Friday 27 Oct. Note that Mon 23 Oct is a public holiday.

Between New Caledonia and Australia

There is expected to be a convergence zone along the Queensland coast on Monday and Tuesday. Avoid.

The squash zone associated with the Tasman High is expected o bring strong SE winds and rough seas between 20and 25S from 175E to the Australian coast on Wed and Thursday (crudely speaking), so wait until after this squash zone.

After the squash zone there is expected to be a ridge with light winds across the route from Sun22 to Wed 25 Oct, and then a prefrontal NW flow.

NZ Coastal Classic

This RACE departs Auckland on Friday for Bay of Island. Expect SW winds, fading at times, especially around Cape Brett.

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If you would like more detail for your voyage, then check metbob.com to see what I offer.

Feedback to bob@metbob.com or txt 6427 7762212

Weathergram text only (and translator) is at weathergram.blogspot.co.nz.

08 October 2017

Disclaimer: Weather is a mix of pattern and chaos; these ideas are from the patterned world.

Its Palolo season this week: On the last quarter moon there is an overnight full tide, the first since the equinox, and that’s the trigger for a spawning of a coral worm called Palolo. They drop off their tails or pod; jade for female and brown for male and these mix together in the swirling tide, with each having a light-sensitive spot that directs them all to the moon a sit sinks in the west. At dawn the pods dissolve allowing eggs and sperm to get together and start a new generation. The rising is only on the turn of that one tide, taking place in a few hours.

If you get the chance ask locals in Vanuatu/Fiji/Samoa/Tonga for more.

FLEET CODE (my annual mention)

FLEET CODE was established to allow a weather map to be sent to the whole Fleet all at once via Morse code transmitted over Shortwave. Fiji Met Service are still manually converting their analysis map into fleet code and, thanks to Mike Harris of Pangolin and the people at saildocs these maps can be downloaded as email and drawn on your own computer as you travel around the South Pacific.

They have an advantage over GRIB files in that they contain convergence zones, as seen by Fiji Met Service meteorologists using satellite imagery to fine tune placements.

When you receive the reply email, use something such as notepad to save the data as a text file and store this, say, on your desktop, as, e.g. fleet.txt

Mike Harris’ PANGOLIN website contains a page which allows you to save a beta version of PhysPlot. Go to www.pangolin.co.nz/physplot . This is a windows program physplot.exe (now called a desktop ap) which can open that file fleet.txt and turn it into a weather map for you.

I don’t use OPENCPN, but apparently you can download the fleet code plug in from opencpn.org website and this gives better viewing of the overall area.

Topics

TC NATE developed over central America and deepened as it travelled north across Gulf of Mexico , and made landfall tonight over Alabama, and is weakening as it goes inland.

Looking at the weekly rain maps from last week and the week before, we can see that there is an increase in area of rain activity in the South Pacific, and in the area and intensity of rain across the equatorial part of the Indian Ocean.

See trmm.gsfc.nasa.gov/trmm_rain/Events/big_global_accumlation.gif for weekly rain maps.

WEATHER ZONES

SPCZ=South Pacific Convergence zone.

The SPCZ has been lingering in place this week from Solomon Islands to Tuvalu/Tokelau area. Its eastern flank may shift south and visit Samoa later this week and extend southeast Southern Cooks next week.

There is likely to be a squash zone of enhance SE winds and south to southeast swells over 3 metres across the French Polynesian area from Wednesday to Saturday (UTC). May as well stay put for this.

Tropical accumulated rainfall for next week can be seen at from windyty.com

Subtropical ridge (STR)

HIGH 1 is expected to travel east along 45 to 40S from east of NZ on Monday to south of French Polynesia by end of the week. It is this high which is forecast to be responsible for the squash zone over FP late this week.

HIGH2 is expected to spread into the central Tasman Sea on Wednesday and then travel northeast across northern NZ on Friday and to east of NZ along 35S from Saturday.

French Polynesia to the west:

Be mindful of that squash zone and increased swells near French Polynesia from Wednesday to Saturday (UTC). May as well stay put for that.

From tropics to NZ or Australia

The Island Cruising Association are supporting the All Points Rally, from all major parts of South Pacific to Opua ending in a ten days of activities 15 to 25 November in Opua. Boats joining the rally are assisted with weather info, resources and planning tools to help make the passage to NZ as easy as possible. See www.bayofislandsmarina.co.nz/all-points-rally/ to register.

Further west there is the GO WEST Rally. From New Caledonia to Australia, culminating with Welcome week events in Bundaberg, 6-12 November. It’s NOT too late to join the rally and enjoy a tailored voyage. See www.downunderrally.com. Registration includes standard Australian clearance fees, and these are around $A400.

In deciding upon a departure date, it’s as simple as 1.2.3:

1.The first factor to consider is the local weather: the SPCZ South Pacific Convergence Zone as it sometimes brings squalls, but is well to the north this week.

Some like to use Minerva reef as an extra staging post since it is 1.5 to 2 days sail south of Tonga, and just out of the tropics (so marine insurance that may be void in the tropics may work in Minerva). But it only shelters you from the waves (so long as they don’t topple over the reef) and not from the wind or rain. It has a passing trough on Monday, and no strong winds this week. .

2.The second factor to watch is the STR, or subtropical ridge, where the HIGHS travel, that zone between the trade winds of the tropics and the disturbed westerlies of the roaring 40s. This zone is usually near 30S, and if there is a big high then on its northern side there is usually an accompanying are of enhanced trade winds, what I call a SQUASH ZONE. This week there is a squash zone expected near French Polynesia later this week.

3.The third factor is weather for arrival. Try to avoid bursts of strong southerly winds and heavy swells during the trip or upon arrival. These come from the Southern Ocean and occur on a different pattern to the passing troughs in the tropics. Sometimes a southerly burst inter-reacts with a tropical trough and things get nasty. Not this week. You can use windyty.com to see expected weather features at your arrival point for the next week, and aim to arrive “in-between active features”, but remember that these outlooks are just ideas, and real world does its own thing.

Let’s apply this 1,2,3 rule to some popular destinations:

Between Tropic and NZ

1 and 2 are OK but 3 has problems. Avoid the SW winds near NZ on Tuesday and Wednesday. Winds are Ok for arrival on Thursday to Sunday, then NOT OK on Mon/16 to Sat 21 Oct next week.

If it takes you around 8 days to get to NZ then consider delaying departure to sometime later next week, or contending with some southerly winds.

Between New Caledonia and Australia

1and 2 are OK this week. 2 and 3 may have problems this or next week depending on your desired port of entry.

A Trough is expected to reach Sydney and fade near Coffs on Tuesday. A stronger trough should reach Sydney on Wednesday and fade near Coffs /Brisbane by Friday.

The HIGH that is expected to be crossing south Tasman sea on 15 to 20 Oct may cause a squash zone of strong easterly winds near 25S near Australian Coast. Avoid arriving there then.

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If you would like more detail for your voyage, then check metbob.com to see what I offer.

Feedback to bob@metbob.com or txt 6427 7762212

Weathergram text only (and translator) is at weathergram.blogspot.co.nz.

01 October 2017

Disclaimer: Weather is a mix of pattern and chaos; these ideas are from the patterned world.

Last month

Sea Surface temperature anomalies may be seen at www.ospo.noaa.gov/data/sst/anomaly/2017/anomnight.8.31.2017.gif

There continues to be more yellow than blue, more area covered by warm anomalies than by cool anomalies, but the blue is getting darker where it matters - along the eastern Equatorial Pacific (a possible LA NINA signal). And there is still a warm river appearing along east coast of South America.

To see how the annual weather cycle and the seasons are working out, take a quick look at the average isobar maps from www.esrl.noaa.gov/psd/map/images/fnl/slp_30b.fnl.html

In September, the subtropical ridge in the southern hemisphere shifted slightly north of its August position, with the disturbed westerly flow as far north as Bass strait to north of North Cape, somewhat further north than normal. A large anomalous LOW remains over South Australia/South Tasman Sea and explains the seasonal variations in the region: the hot NW winds for NE Australia, and the wet westerlies for North island and wet NE winds for eastern South Island.

There is a purple anomaly from Caribbean to Eastern USA - That’s IRMA MARIA and their associates.

The anomaly map shows that the ITCZ is further north than normal---this is a LA NINA trait.

The Atlantic hurricanes also show in the monthly rain map at trmm.gsfc.nasa.gov/trmm_rain/Events/thirty_day.html

Topics

Remains of TC MARIA have travelled more than half way across the North Atlantic, and may affect UK in a few days. Otherwise, things seem to be quietening down for now. Then again, a new tropical system is expected to form off the Mexican west coast later this week.

Rainfall for the past week compared with last week, shows the paths of IRMA and MARIA with a peak over Puerto Rica. Also a build-up of rain near 5S in the Indian Ocean. See trmm.gsfc.nasa.gov/trmm_rain/Events/big_global_accumlation.gif

WEATHER ZONES

SPCZ=South Pacific Convergence zone.

The SPCZ is expected to stay in place this week from Solomon Islands to Tuvalu/Tokelau area. Its eastern flank may shift south towards Samoa by this weekend.

The Trough that is travelling to east of NZ tonight is expected to continue east and fade well to the south of the tropics on Tue/Wed UTC. It is followed by a day or so of 3 metres + southerly swells from the Southern Ocean reaching as far north as 20S for Tuesday. These swells are gentle giants with a period of 12 seconds, so very well spaced apart.

Another trough is expected to travel east across Southern Cooks and French Polynesia late this week, and this may form a LOW further south.

Subtropical ridge (STR)

HIGH 1 is expected to move across Tasman Sea along 30S on Monday and Tuesday and then fade over northern NZ on Thursday and Friday. HIGH 2 is expected to spread into the South Tasman Sea on Thursday and then travel east across South Island and rebuild east of New Zealand on Friday and Saturday.

French Polynesia to the west:

There may be some strong SE winds near Bora Bora on local Sunday and Monday.

The next obstacle to consider appears from around the end of the week -- and is a travelling trough over Southern Cooks / French Polynesia.

If tossing up between going to Samoa or Tonga, then pick Tonga and avoid the SPCZ.

Between NZ and the tropics:

Avoid the strong W/SW winds and rough seas near NZ on Monday, these should ease away on Tuesday.

Then there should be a window of opportunity for getting to northern NZ from Tue 3 to Sat 7 October thanks to passing Highs.

There is expected to be a trough near northern NZ around Sun/Mon 8/9 Oct with strong NE winds and some rain.

Then there should be another period of acceptable weather to get to northern NZ until the next trough arrives around sat 14 Oct.

Between New Caledonia and Australia

It’s Ok to go to Bundaberg or Brisbane, BUT avoid arriving there on Thursday 5 October, for that is when there may be a venting of the heat trough. This trough is expected to travel east across the eastern seaboard of Australia on Thursday, and deepen into a Tasman Low offshore on Friday. This Low should then travel east to northern NZ by 9/10 October.

The trough may bring squalls and lightning to Bundaberg and Brisbane ion Thursday, followed by a brief period of SW winds, so avoid.

Apart from that, the Tasman low is NOT expected to have much impact on the New Caledonia to Bundaberg or Brisbane route.

Vanuatu Volcano

And, for the goodness of your health, stay away from Ambae Island and its active volcano, Manaro Voul.

This island, east of Espiritu Santo, inspired James Michener’s mythical Bali Hai.

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If you would like more detail for your voyage, then check metbob.com to see what I offer.

Feedback to bob@metbob.com or txt 6427 7762212

Weathergram text only (and translator) is at weathergram.blogspot.co.nz.

Weathergram with graphics is at metbob.wordpress.com, Click FOLLOW at bottom right to subscribe.